This transistor, 2N208, was the original oval welded package type
designed and built at TI. The work was performed in 1954-7 as part of the
effort on U.S. Army Signal Corps Contract No: DA-36-039-SC-54703.

The contract was for Industrial Preparedness Study on Silicon
Transistors, usually referred to as a Manufacturing Methods contract,
covering the period October, 1954, to April, 1957. The objective was to
design three grown junction silicon transistors for use in military
equipment and the procedures and tooling for their fabrication and testing.
A welded package was required to replace the original TI solder sealed
package. Another major improvement resulting from this work was a process
for soldering the silicon bar to the header leads. The contract
specification was based on the original TI901-2 transistors and engineering
estimates of what was needed and might be achieved. This device, designated
Type 22-B, was covered by MIL-T-12679A/22B (Sig C) and was registered as
RETMA type 2N208. In late 1954, TI super ceded the 901-2 types with 903-5
types. These were designed into the early circuit applications for
production; therefore, the 2N208 was built only for contract requirements.
With the welded package, TI introduced and registered types 2N117-9 with
the same or slightly tighter parameter limits as the 903-5. Military
specifications were issued for the 2N117, 8 & 9, and TI became the first
qualified supplier of Mil Spec silicon transistors. The three transistors
were checked on 1/3/86. Current gain (beta) was still good, and there
appeared to be no serious degradation of breakdown voltage. A copy of the
contract final report and the 1/3/86 test results are in the Artifact
Historical Files.